Plant Biology and Classification

Anthoceros has a sporophyte with a foot and intercalary meristem. Marchantia has gemma cups. Pteris (a fern) has sori covered by a false indusium. Ginkgo is a gymnosperm (embryophytic, tracheophytic, archegoniate).

The thallus is dorsiventral and closely appressed to the substrate. 

Marchantia is a large liverwort and is also called as umbrella liverwort. Marcantia is dioicous and hence has seperate male and female plants.

Sphagnum is one of the most important plant genera in the world. Sphagnum is one of the few bryophyte genera able to dominate an ecosystem. A healing ointment prepared by Sphagnum leaves mixed with grease is used in the treatment of cuts and wounds. The decoction prepared by boiling dried Sphagnum in water, is used in the treatment of acute haemorrhage. This decoction is used to cure diseases of eyes. The lakes where sphagnum grows are called as Sphagnum bogs. These are well known to produce peat in acidic water. The bog water is antiseptic and has astringent properties. Sphagnum exhibit strong antibacterial properties against Gaffkeya tetragena and Staphylococcus aureus. Sphagnum peat is suitable for production of low and intermediate BTU gas as well as hydrogen , ethylene , natural gas , methanol and gasoline. Sphagnum is used as an effective filtering and absorption agent for the treatment of waste water and effluent of factories with acid and toxic discharge consisting of heavy metals particularly Ag, Pb, Cu , Hg, Fe , Sb and organic substances like detergents, dyes, microorganisms and soils.

Peat is a dead form of Sphagnum moss. The lakes where sphagnum grows are called as Sphagnum bogs. These are well known to produce peat in acidic water.

Sphagnum is one of the most important plant genera in the world. 
Sphagnum tends to acidify its surroundings. The acidity inhibits bacterial and fungal growth.
Living Sphagnum plants have an impressive water holding potential, with a number of species able to hold 20 or more times their own weight in water. Given the ability to absorb large amounts of water Sphagnum plays a significant role in water regulation. Sphagnum absorbs a vast quantity of water during any heavy downpour or after snow melt and then releases much of that water in a more gradual flow over a much longer period.
Peat is a valuable fuel like coal, consists of Sphagnum plants, which got compacted and fossilized over the past thousands of years.

Sphagnum that generally grows in bogs are slightly antiseptic and can absorb large amount of water i.e., upto 18 times its weight. On account of these properties they may be used for filling absorbent bandage in place of cotton, in the hospitals. The plants absorb and hold water in them. For these properties they are used in seed beds and green houses to root cuttings. They are also used to maintain high soil acidity required by certain plants.

Bryophytes can colonize any rock, soil or any barren land. They have the ability to absorb water from rain and mist and to trap nutrients dissolved in rain and mist drops. They Dead and decaying bryophytes release nutrients and make a path for soil formation. Hence, they are the first organism in primary succession. Thus, the correct answer is option B.

Sphagnum (peat moss) is of significant economic importance because it is used as fuel, as packing material for shipping plants, and for its high water-holding capacity.

Sphagnum efficiently absorbs moisture because of its close overlapping leaves and sponge-like matting of the branches around the stem, and also the microscopic structure of the leaves. The elongated living cells form a network running throughout the leaf but it is a second set of cells, dead and empty, that provide the plant’s capacity for absorption. Their porous cell walls allow water to flow in and inflate them. Each cell can absorb up to 25 times its own weight of liquid. Sphagnum has found use since ancient times in home-made sanitary towels and as a form of nappy. Sphagnum has been used to staunch wounds for over 1,000 years. Scottish soldiers used it at the battle of Flodden in 1513. Its use for wounds waned until the 1914–18 war, when it soon became obvious to surgeons that the need for dressings would be immense due to the unexpected numbers of military wounded.

Bryophytes are known as 'amphibians of plant kingdom' because they are adapted to land as well as water habitats. In their vegetative structure, bryophytes have become adapted to land. But they depend on water for sexual reproduction because the swimming habit is retained by their sperms.

Several plant families, including Euphorbiaceae, Apocynaceae, and Asclepiadaceae, contain species that produce latex or oils which can be processed into biofuels.